Pregnant Jessica Alba raises belly laughs in birthing class sketch with Jimmy Kimmel - where HE has a child called Pippa Middleton

By Jody Thompson

Scroll down to watch the sketch...

Belly laughs: Pregnant Jessica Alba raises more than a few giggles in her birthing class sketch with comedian Jimmy Kimmel which aired in the U.S. last night

Heavily-pregnant Jessica Alba showed she was still game for a laugh literally days away from the birth of her second child by taking part in a hilarious comedy birthing class sketch on Jimmy Kimmel's U.S. chat show last night.

Jimmy stands in for Jessica's husband Cash Warren in the skit and joins sultry Jessica, 30, at her birthing class.

In the hilarious sketch on Jimmy Kimmel Live!, Jimmy, 43, starts goofing around as soon as he gets there, asking the birthing educator taking the class: 'How are babies made?'

Gather round: Kimmel was pretending he was standing for Jessica's husband, Cash Warren

This is how it feels: The funnyman was asked to don an 'empathy belly'

He then is asked to wear an 'empathy belly' by the teacher and when she asks if any of the mothers-to-be wanted to volunteer to go through a mock birth, Jimmy puts his hand up.

As Jessica takes on the role of the father and helps him push, Jimmy moans: 'Why did you do this to me?'

To which she replies: 'You asked for it!'

After lots of pushing, Kimmel eventually gives birth to the fake baby, and says: 'I want to name it Pippa Middleton.'

Keep pushing: Jimmy then goes through with a mock birth while Jessica pretends to be the father

Fierce: The mother-of-one certainly put Jimmy though his pregnancy paces

And breathe: Jimmy put a lot of effort into the fake birth

In real life, Machete star Jessica is due within the next few weeks, but she's currently busy too promoting new movie Spy Kids: All The Time In The World 4D.

She's understood to be expecting another girl and is planning a 'hypnobirth', and explained to TV chat show host and comedian Ellen Degeneres what it entailed.

She said: 'Basically my husband takes me through sort of a meditation. So he's like saying, 'You're relaxed and you're floating on clouds', while you're going through labour and your contractions.'

Can I hold her? One of the birthday class students can't help corpsing

A father's love: Jimmy cradles the newly mock-born baby

What's in a name? Jimmy named his newborn plastic daughter after Pippa Middleton

She added: 'He just sort of does a guided meditation. I'm just concentrating on breathing and staying relaxed because it's when you get tense that makes the whole labor worse and more painful. That's all it is. It's not like a weird thing.

'I actually did this with Honor…it is kind of a way to relax and know that the contraction will only last for so long. You just need to concentrate on the breathing and just the sound of his voice.

'You know, normally I want to strangle him, but at that moment it's sort of calming and wonderful.'

Jessica's film Spy Kids: All The Time In the World 4D meanwhile opens in the UK in 19 August.

Plugging away: Jessica was also properly interviewed on Jimmy Kimmel Live! ahead of the release of her new movie Spy Kids: All The Time In The World 4D